Representative embodiments relate to methods of manufacturing semiconductor devices. More particularly, representative embodiments relate to methods of manufacturing semiconductor devices including a gate structure.
In a gate-last process, a dummy gate structure including a dummy gate insulation layer pattern and a dummy gate electrode may be formed, and a spacer may be formed on a sidewall of the dummy gate structure. The spacer may be oxidized when removing a photoresist pattern serving as an etching mask in various processes. Additionally, a trench may be formed at an upper portion of a substrate adjacent to the dummy gate structure. Surfaces of the substrate defining the trench are cleaned using a cleaning solution. As a result, the oxidized spacer adjacent to the trench may be removed by the cleaning solution thereby forming a void. Thus, when the dummy gate electrode is removed, an etching solution may flow through the void onto the substrate and thereby damage the substrate.